Domain-Specific Outcomes for Stroke Clinical Trials: What the Modified Rankin Isn't Ranking

Association Between Real-World Actigraphy and Poststroke Motor Recovery

BACKGROUND

Stroke is a leading cause of long-term disability, but advances for rehabilitation have lagged those for acute treatment. Large biological studies (eg, omics) may offer mechanistic insights for recovery but require collecting detailed recovery phenotypes at scale, for example, in thousands of people with minimal burden for participants and researchers. This study investigates the concurrent validity between remotely collected wearable sensor data and in-clinic assessments of motor recovery poststroke.

METHODS

Utilizing a large, harmonized multisite dataset of adults at various stages of recovery poststroke, we analyzed cross-sectional (N=198; from 0 to >52 weeks) and longitudinal (N=98; from 0 to 26 weeks) changes in the use ratio, the Action Research Arm Test, and the Fugl-Meyer Assessment upper extremity subscale. The use ratio is the ratio of the time the paretic arm is active divided by the time the nonparetic arm is active.

RESULTS

Our findings indicate strong concurrent validity of the use ratio, the Action Research Arm Test, and the Fugl-Meyer Assessment upper extremity subscale both cross-sectionally (differences between people) and longitudinally (changes within a person), for example, r=0.87 (95% CI, 0.80-0.91) at 0 to 6 weeks, declining to r=0.58 (95% CI, 0.39-0.72) at ≥52 weeks for correlations between use ratio and Action Research Arm Test.

CONCLUSIONS

Although the use ratio strongly correlated with the Fugl-Meyer Assessment upper extremity subscale and Action Research Arm Test early after stroke, these correlations reduced with longer elapsed time poststroke. This decreasing correlation might be explained by the increasing influence that personal and environmental factors play as recovery progresses.

Genomics of stroke recovery and outcome

The understanding of genomics has improved tremendously during the last decades. The concept of recovery and outcome after stroke has also progressed during this time. However, the connection between genomics and stroke recovery has only begun to emerge in a more structural and comprehensive way. Different types of outcomes and recovery occur after stroke. This depends on domain of neurological deficit, severity, resilience, receptivity for rehabilitation measures, and concomitant morbidity. Methods for assessing stroke patients' prognosis depend on these factors. Different genetic approaches are possible and there is an increasing need for linking genetic findings to other omics as well as to clinically meaningful results. This review addresses recent advances and views in clinical genomics of stroke recovery and outcome in humans with focus on current and previous studies, concepts, and future perspectives.

Association Between Changes in White Matter Volume Detected With Diffusion Tensor-Based Morphometry and Motor Recovery After Stroke

BACKGROUND AND OBJECTIVES

Diffusion tensor-based morphometry (DTBM) provides a more accurate assessment of volumetric changes in white matter structures than conventional T1-based TBM techniques. We sought to determine whether DTBM could detect volume loss in the corticospinal tract (CST) and whether this marker was associated with impaired stroke recovery.

METHODS

Retrospective clinical MRI scans were obtained from a cohort of participants enrolled in a natural history study with acute anterior circulation ischemic stroke and unilateral arm impairment (NIH Stroke Scale [NIHSS] arm motor item score ≥2). Maps of the change in fractional anisotropy (delta FA) and the DTBM log of the Jacobian (LnJ, representing volumetric change) between scans, acquired <36 hours and 30 days after stroke, were computed. Voxel-wise Spearman rank-based analysis identified clustered regions of interest (ROIs) where the delta FA and LnJ from baseline to 30 days correlated with individual arm motor recovery scores on the NIHSS from baseline to 30 days. Qualitative comparisons were made between delta FA and LnJ maps for good and poor recovery groups (delta NIHSS arm item score ≥2 or <2, respectively) in reference to controls.

RESULTS

Twenty-one participants with anterior circulation stroke were evaluated (mean age 63.6 years, median NIHSS arm motor item score 4, 48% female). Voxel-wise statistical maps identified 2 ROIs for delta FA and 4 ROIs for LnJ showing strong correlations with arm motor recovery (range of Spearman ρ = 0.77-0.81, all p < 0.01). The delta FA ROIs included the corona radiata and adjacent white matter, whereas LnJ ROIs included the centrum semiovale, corona radiata, internal capsule, and pons. Visual inspection of the average delta FA map from participants with poor arm motor recovery showed diffuse changes in the CST and adjacent subcortical regions while LnJ maps demonstrated more focal CST changes, particularly in the brainstem and internal capsule.

DISCUSSION

DTBM detects focal volume loss in the CST over the first 30 days after stroke likely related to Wallerian degeneration. These volumetric changes may provide complementary information to FA in characterizing white matter loss after stroke. Like FA, DTBM shows strong correlations with arm motor recovery that could be useful for predicting recovery after stroke.

Evaluation of the Prevalence of Sleep Disorders and Their Association with Stroke: A Hospital-Based Retrospective Study

Background: Sleep disturbances are prevalent among stroke survivors, significantly impacting their recovery and quality of life. This study aimed to evaluate the prevalence of sleep disorders, sleep quality, risk of obstructive sleep apnea (OSA), and daytime sleepiness among stroke survivors and to identify potential associations with clinical and demographic factors. Materials and Methods: A retrospective observational study analyzed adult stroke survivors (aged ≥ 18 years) attending neurology clinics at our institution from November 2022 to November 2024. The primary outcome measures included overall sleep quality, sleep apnea and daytime sleepiness assessment. Data were collected using validated Arabic versions of the Pittsburgh Sleep Quality Index (PSQI), STOP-Bang Questionnaire, and Epworth Sleepiness Scale (ESS). Statistical analyses, including Chi-square tests and t-tests, were performed using SPSS version 30.1. Results: A total of 100 stroke survivors, mostly aged 40-60 years, were recruited in our study. The prevalence of sleep disorders was 60.0%, with poor sleep quality reflected by a mean global PSQI score of 9.13 ± 14.40. Additionally, 19.0% were at high risk of OSA, and 24.0% experienced abnormal daytime sleepiness. While no statistically significant associations were found between sleep disorders and clinical or demographic factors, trends indicated higher sleep disorder prevalence in those with hemorrhagic stroke and high-risk OSA profiles. Conclusions: Our study highlights a high prevalence of sleep disorders among stroke survivors, emphasizing the need for regular sleep assessments. Future studies should explore objective assessments and larger sample sizes to validate these findings and to assess their potential implication in stroke recovery and quality of life.

Adiposity and domain-specific stroke recovery: A Mendelian randomization study

INTRODUCTION

While adiposity is an established risk factor for incident ischemic stroke, its influence on functional recovery after stroke is uncertain. We leveraged Mendelian randomization (MR) to examine the causal effects of body mass index (BMI) and waist-to-hip ratio (WHR) on post-stroke motor, cognitive, and global recovery.

MATERIALS AND METHODS

Genetic proxies for BMI and WHR were obtained from a genome-wide association study (GWAS) meta-analysis of the GIANT consortium and the UK Biobank (n = 806,834). The primary outcomes were longitudinal trajectories of three National Institutes of Health Stroke Scale (NIHSS) measures assessed over a 2-year period: motor function subscores, cognitive performance subscores, and total NIHSS scores (as a measure of global recovery). Genetic associations with these stroke recovery outcomes were obtained from a GWAS conducted within the VISP trial of mild ischemic stroke (n = 1270). MR effects were estimated using the inverse-variance weighted method.

RESULTS

A 1-standard deviation (SD) increase (~4.8 kg/m2) in genetically predicted BMI associated with lower odds of post-stroke motor improvement (OR = 0.37, 95% CI = 0.19-0.72; p = 0.003). Similarly, a genetically predicted increase in BMI was associated with worse cognitive (β = -0.12, 95% CI = -0.21, -0.03; p = 0.009) and global recovery (β = -0.36, 95% CI = -0.59, -0.13; p = 0.002). Associations between genetically predicted WHR and post-stroke recovery were directionally concordant but were not statistically significant (p > 0.05).

DISCUSSIONS AND CONCLUSIONS

Human genetic evidence suggests that elevated adiposity negatively impacts multiple post-stroke outcomes, including motor function, cognition, and overall recovery. The biological pathways underlying these associations warrant further investigation.

Prevalence, Trajectory, and Factors Associated With Patient-Reported Nonmotor Outcomes After Stroke: A Systematic Review and Meta-Analysis

Importance

The evidence on nonmotor outcomes after acute ischemic stroke and intracerebral hemorrhage (ICH) is limited and domain-specific. The prevalence, natural history, and factors associated with nonmotor outcomes across multiple domains are unclear.

Objective

To synthesize the published data and to identify the prevalence, natural history, and factors associated with multidomain nonmotor outcome burden in patients with stroke.

Data Sources

A search of PubMed, MEDLINE, EMBASE, and PsycINFO databases between January 1999 to June 2023 was supplemented by search of bibliographies of the key articles.

Study Selection

The analysis included prospective cohort studies that reported nonmotor outcomes across 10 domains: anxiety, depression, fatigue, sleep disturbance, social participation, pain, bladder dysfunction, bowel dysfunction (constipation and fecal incontinence), and sexual dysfunction assessed by patient-reported scales.

Data Extraction and Synthesis

Two reviewers independently assessed studies, extracting baseline data, nonmotor prevalence, and follow-up information. Pooled prevalence of nonmotor outcomes was estimated using random-effects models. Meta-regression models were used to analyze natural history and factors associated with nonmotor outcomes. Subgroup analysis was used to assess prevalence by symptom description within each nonmotor domain. Publication bias and study quality were assessed using funnel plots and the Newcastle-Ottawa scale.

Results

A total of 279 prospective cohort studies met the inclusion criteria (117 440 participants with stroke; median [IQR] age, 65 [59-70] years; 209 of 279 studies with more male than female participants) with a nonmotor outcome follow-up period ranging from 30 days to 10 years after stroke. The most prevalent adverse nonmotor outcomes by pooled prevalence were sleep disturbance (59.9%; 95% CI, 53.9%-63.9%), sexual dysfunction (59.8%; 95% CI, 50.0%-69.5%), constipation (58.2%; 95% CI, 53.9%-62.6%), reduced social participation (56.5%; 95% CI, 52.1%-60.8%), bladder dysfunction (45.9%; 95% CI, 38.0%-53.8%), and fatigue (45.2%; 95% CI, 40.7%-49.5%). Meta-regression analysis showed no significant improvement over time for most nonmotor outcomes, except pain (coefficient = -11.0%; P = .05) and sexual dysfunction (coefficient = -24.1%; P < .001). The heterogeneity ranged between 52% and 98% across all studies. The common factors associated with adverse nonmotor outcomes were female sex, studies with mixed stroke cohort (ischemic stroke or ICH), and older age.

Conclusions and Relevance

Patient-reported nonmotor outcomes were common after stroke. Sexual dysfunction, sleep disturbance, constipation, reduced social participation, bladder dysfunction, and fatigue were most prevalent. These adverse outcomes often persisted over time, especially in women, older adults, and those in studies with mixed stroke cohorts.

Low-dose colchicine for stroke prevention: A systematic overview of systematic reviews and meta-analyses

BACKGROUND

Stroke incidence remains a significant concern despite optimized prevention strategies. Colchicine shows potential for improving stroke prevention globally.

AIMS

To summarize efficacy and safety estimates from systematic reviews and meta-analyses (SRMAs) of randomized controlled trials (RCTs) comparing colchicine to usual care or placebo for stroke prevention.

METHODS

We conducted an overview of SRMAs according to the Preferred Reporting Items for Overviews of Reviews guidelines through a systematic search in Pubmed, Embase, and the Cochrane Library. Statistical analysis was performed using RevMan Web. Heterogeneity was assessed with I² statistics.

RESULTS

Thirty-two studies were included. Colchicine significantly reduced stroke recurrence (RR 0.46; 95 % CI 0.41-0.52; p < 0.0001; I² = 0 %; OR 0.44, 95 % CI 0.36-0.55; p < 0.0001; I² = 0 %) but increased gastrointestinal adverse events (RR 1.54, 95 % CI 1.33-1.79; p < 0.0001; I² = 63 %; OR 1.60, 95 % CI 1.08-2.38; p = 0.0007; I² = 82 %). Most SRMAs (93.75 %) showed reduced stroke incidence (RR 0.26-0.54), while 65.22 % reported increased gastrointestinal events (RR 1.05-2.66). No significant differences were observed in mortality, infection or cancer rates. Overall quality was appraised as high in 28.12 %, moderate in 6.25 %, low in 40.06 %, and critically low in 25 % of SRMAs. Data were primarily derived from seven RCTs with low risk of bias.

CONCLUSIONS

Moderate-quality evidence supports colchicine's benefits and reasonable safety for preventing stroke among high-risk populations. However, stroke was not the primary endpoint in analyzed studies. RCTs directly assessing colchicine for stroke prevention are warranted.

Standardizing Domains and Metrics of Stroke Recovery: A Systematic Review

BACKGROUND AND AIMS

Measuring stroke recovery poses a significant challenge, given the complexity of the recovery process. We aimed to identify a standardized and data-driven set of metrics of stroke rehabilitation in the literature that ensures the inclusion of all recovery domains and subdomains in the literature.

METHODS

A systematic review was conducted by four reviewers using the PRISMA guidelines on PubMed, MEDLINE, and Embase for stroke recovery articles between 2004 and 2024. The inclusion criteria comprised experimental/observational studies, including ischemic and hemorrhagic stroke. All studies had ≥20 participants who were ≥18 years of age, and had a follow-up of ≥3 months. Outcomes included demographics, geographic origin, stroke mechanism, domains and subdomains, metrics used, and follow-up. A bias assessment was performed using the Newcastle-Ottawa Scale and the Cochrane Risk of Bias 2.0 tool. This study was registered with PROSPERO (CRD42024551753).

RESULTS

Our search included 324 studies with a sample of 85,156 participants. The study identified seven domains (perception, physical and motor function (PF), speech and language (S&L), cognition, activities of daily living (ADL), quality of life (QoL), and social interaction) and 96 constituent subdomains that encompass the complete landscape of the stroke recovery literature identified. The domains of PF and ADL constituted the vast share of the literature, albeit reducing in their relative representation over time, while domains such as perception and QoL have been increasingly studied since 2004. Using the domains, the study identified the set and frequency of all commonly used metrics to measure stroke recovery in the literature, of which the NIHSS (n = 72), BI (n = 55), and mRS (n = 51) were the most commonly used. We identified eighteen standard metrics that ensure the inclusion of all seven domains and 96 subdomains. Summary of Review and Conclusions: The identified set of domains and metrics within this study can help inform further clinical research and decision-making by providing a standardized set of metrics to be used for each domain. This approach ensures lesser represented domains and subdomains are also included during testing, providing a more complete view and measure of stroke recovery.

Prospective evaluation of the relationship between cognition and recovery outcomes after cardiac arrest

PURPOSE

Cognitive function is often impaired for cardiac arrest (CA) survivors due to hypoxic-ischemic brain injury. Whether cognitive impairment at hospital discharge is associated with recovery defined as functional status and fatigue measured at 1-month post-discharge is not known.

METHODS

Consecutive CA patients admitted at an academic center (May 14, 2021-June 23, 2023) were assessed for cognitive impairment (modified Telephone Interview for Cognitive Status, TICS-m < 33) and depressive symptoms (8-item Patient Health Questionnaire) at hospital discharge. Poor functional status (primary outcome; modified Rankin Scale, mRS > 3) and fatigue severity (patient-reported outcome; Modified Fatigue Impact Scale) were assessed 1-month post-discharge. Hierarchical regressions tested associations of cognitive function with outcomes.

RESULTS

Of 112 participants (mean age 54.4 ± 14.8; 38% female; 43% White race, 20% Black race, 29% Hispanic ethnicity) completing discharge TICS-m, 63 (56%) had indicated cognitive impairment, and 68 (61%) had poor 1-month functional outcome. Worse discharge cognitive function was independently associated with a higher risk of poor 1-month functional outcome (OR = 0.88, 95% CI [0.79, 0.98], p = 0.02) after adjusting for age, education, sex, race, ethnicity, length of hospital stay, comorbidities, and depressive symptoms. Fatigue severity lacked significant associations with cognitive function, but was associated with depressive symptoms (B = 1.03 [0.00, 2.05], p = 0.04).

CONCLUSION

Cognitive function at discharge after CA was significantly and independently associated with functional outcome 1 month after hospital discharge. Psychological distress contributed to fatigue severity. This highlights the need for screening and addressing cognitive and emotional problems pre-hospital discharge.

Genetic Variation and Stroke Recovery: The STRONG Study

BACKGROUND

Genetic association studies can reveal biology and treatment targets but have received limited attention for stroke recovery. STRONG (Stroke, Stress, Rehabilitation, and Genetics) was a prospective, longitudinal (1-year), genetic study in adults with stroke at 28 US stroke centers. The primary aim was to examine the association that candidate genetic variants have with (1) motor/functional outcomes and (2) stress-related outcomes.

METHODS

For motor/functional end points, 3 candidate gene variants (ApoE ε4, BDNF [brain-derived neurotrophic factor], and a dopamine polygenic score) were analyzed for associations with change in grip strength (3 months-baseline), function (3-month Stroke Impact Scale-Activities of Daily Living), mood (3-month Patient Health Questionnaire-8), and cognition (12-month telephone-Montreal Cognitive Assessment). For stress-related outcomes, 7 variants (serotonin transporter gene-linked promoter region, ACE [angiotensin-converting enzyme], oxytocin receptor, FKBP5 [FKBP prolyl isomerase 5], FAAH [fatty acid amide hydrolase], BDNF, and COMT [catechol-O-methyltransferase]) were assessed for associations with posttraumatic stress disorder ([PTSD]; PTSD Primary Care Scale) and depression (Patient Health Questionnaire-8) at 6 and 12 months; stress-related genes were examined as a function of poststroke stress level. Statistical models (linear, negative binomial, or Poisson regression) were based on response variable distribution; all included stroke severity, age, sex, and ancestry as covariates. Stroke subtype was explored secondarily. Data were Holm-Bonferroni corrected. A secondary replication analysis tested whether the rs1842681 polymorphism (identified in the GISCOME study [Genetics of Ischaemic Stroke Functional Outcome]) was related to 3-month modified Rankin Scale score in STRONG.

RESULTS

The 763 enrollees were 63.1±14.9 (mean±SD) years of age, with a median initial National Institutes of Health Stroke Scale score of 4 (interquartile range, 2-9); outcome data were available in n=515 at 3 months, n=500 at 6 months, and n=489 at 12 months. At 1 year poststroke, the rs6265 (BDNF) variant was associated with poorer cognition (0.9-point lower telephone-Montreal Cognitive Assessment score, P=1×10-5). For stress-related outcomes, rs4291 (ACE) and rs324420 (FAAH) were risk factors linking increased poststroke stress with higher 1-year depression and PTSD symptoms (P<0.05), while rs4680 (COMT) linked poststroke stress with lower 1-year depression and PTSD. Findings were unchanged when considering stroke subtype. STRONG replicated GISCOME: rs1842681 was associated with lower 3-month modified Rankin Scale score (P=3.2×10-5).

CONCLUSIONS

This study identified genetic associations with cognitive function, depression, and PTSD 1 year poststroke. Genetic susceptibility to PTSD and depressive symptoms varied according to the amount of poststroke stress, underscoring the critical role of lived experiences in recovery. Together, the results suggest that genetic association studies provide insights into the biology of stroke recovery in humans.

Disability and Recurrent Stroke Among Participants in Stroke Prevention Trials

Importance

Stroke secondary prevention trials have disproportionately enrolled participants with mild or no disability. The impact of this bias remains unclear.

Objective

To investigate the association between poststroke disability and the rate of recurrent stroke during long-term follow up.

Design, Setting, and Participants

This cohort study is a post hoc analysis of the Prevention Regimen For Effectively Avoiding Second Strokes (PRoFESS) and Insulin Resistance Intervention After Stroke (IRIS) secondary prevention clinical trial datasets. PRoFESS enrolled patients from 2003 to 2008, and IRIS enrolled patients from 2005 to 2015. Data were analyzed from September 23, 2023, to May 16, 2024.

Exposure

The exposure was poststroke functional status at study baseline, defined as modified Rankin Scale (mRS; range, 0-5; higher score indicates more disability) score of 0 vs 1 to 2 vs 3 or greater.

Main Outcomes and Measures

The primary outcome was recurrent stroke. The secondary outcome was major cardiovascular events (MACE), defined as recurrent stroke, myocardial infarction, new or worsening heart failure, or vascular death.

Results

A total of 20 183 PRoFESS participants (mean [SD] age, 66.1 [8.5] years; 12 931 [64.1%] male) and 3265 IRIS participants (mean [SD] age, 62.7 [10.6] years; 2151 [65.9%] male) were included. The median (IQR) follow-up was 2.4 (1.9-3.0) years in PRoFESS and 4.7 (3.2-5.0) years in IRIS. In PRoFESS, the recurrent stroke rate was 7.2%, among patients with an mRS of 0, 8.7% among patients with an mRS of 1 or 2, and 10.6% among patients with an mRS of 3 or greater (χ22 = 27.1; P < .001); in IRIS the recurrent stroke rate was 6.4% among patients with an mRS of 0, 9.0% among patients with an mRS of 1 or 2, and 11.7% among patients with an mRS of 3 or greater (χ22 = 11.1; P < .001). The MACE rate was 10.1% among patients with an mRS of 0, 12.2% among patients with an mRS of 1 or 2, and 17.2% among patients with an mRS of 3 or greater (χ22 = 103.4; P < .001) in PRoFESS and 10.9% among patients with an mRS of 0, 13.3% among patients with an mRS of 1 or 2, and 15.3% among patients with an mRS of 3 or greater (χ22 = 5.8; P = .06) in IRIS. Compared with patients with an mRS of 0, patients with an mRS of 3 or greater had increased hazard for recurrent stroke in PRoFESS (hazard ratio [HR], 1.63; 95% CI, 1.38-1.92; P < .001) and in IRIS (HR, 1.91; 95% CI, 1.28-2.86; P = .002). There was also increased hazard for MACE in PRoFESS (HR, 1.90; 95% CI, 1.66-2.18; P < .001) and in IRIS (HR, 1.45; 95% CI, 1.03-2.03; P = .03).

Conclusions and Relevance

This cohort study found that higher baseline poststroke disability was associated with increased rates of recurrent stroke and MACE. Including more patients with greater baseline disability in stroke prevention trials may improve the statistical power and generalizability of these studies.

Prevalence, patterns, and predictors of patient-reported non-motor outcomes at 30 days after acute stroke: Prospective observational hospital cohort study

BACKGROUND

Adverse non-motor outcomes are common after acute stroke and likely to substantially affect quality of life, yet few studies have comprehensively assessed their prevalence, patterns, and predictors across multiple health domains.

AIMS

We aimed to identify the prevalence, patterns, and the factors associated with non-motor outcomes 30 days after stroke.

METHODS

This prospective observational hospital cohort study-Stroke Investigation in North and Central London (SIGNAL)-identified patients with acute ischemic stroke or intracerebral hemorrhage (ICH) admitted to the Hyperacute Stroke Unit (HASU) at University College Hospital (UCH), London, between August 1, 2018 and August 31, 2019. We assessed non-motor outcomes (anxiety, depression, fatigue, sleep, participation in social roles and activities, pain, bowel function, and bladder function) at 30-day follow-up using the Patient-Reported Outcome Measurement Information System-Version 29 (PROMIS-29) scale and Barthel Index scale.

RESULTS

We obtained follow-up data for 605/719 (84.1%) eligible patients (mean age 72.0 years; 48.3% female; 521 with ischemic stroke, 84 with ICH). Anxiety (57.0%), fatigue (52.7%), bladder dysfunction (50.2%), reduced social participation (49.2%), and pain (47.9%) were the commonest adverse non-motor outcomes. The rates of adverse non-motor outcomes in ⩾ 1, ⩾ 2 and ⩾ 3 domains were 89%, 66.3%, and 45.8%, respectively; in adjusted analyses, stroke due to ICH (compared to ischemic stroke) and admission stroke severity were the strongest and most consistent predictors. There were significant correlations between bowel dysfunction and bladder dysfunction (κ = 0.908); reduced social participation and bladder dysfunction (κ = 0.844); and anxiety and fatigue (κ = 0.613). We did not identify correlations for other pairs of non-motor domains.

CONCLUSION

Adverse non-motor outcomes were very common at 30 days after stroke, affecting nearly 90% of evaluated patients in at least one health domain, about two-thirds in two or more domains, and almost 50% in three or more domains. Stroke due to ICH and admission stroke severity were the strongest and most consistent predictors. Adverse outcomes occurred in pairs of domains, such as with anxiety and fatigue. Our findings emphasize the importance of a multi-domain approach to effectively identify adverse non-motor outcomes after stroke to inform the development of more holistic patient care pathways after stroke.

Genome-Wide Association Studies of 3 Distinct Recovery Phenotypes in Mild Ischemic Stroke

BACKGROUND AND OBJECTIVES

Stroke genetic research has made substantial progress in the past decade. Its recovery application, however, remains behind, in part due to its reliance on the modified Rankin Scale (mRS) score as a measure of poststroke outcome. The mRS does not map well to biological processes because numerous psychosocial factors drive much of what the mRS captures. Second, the mRS contains multiple disparate biological events into a single measure further limiting its use for biological discovery. This led us to investigate the effect of distinct stroke recovery phenotypes on genetic variation associations with Genome-Wide Association Studies (GWASs) by repurposing the NIH Stroke Scale (NIHSS) and its subscores.

METHODS

In the Vitamin Intervention for Stroke Prevention cohort, we estimated changes in cognition, motor, and global impairments over 2 years using specific measures. We included genotyped participants with a total NIHSS score greater than zero at randomization and excluded those with recurrent stroke during the trial. A GWAS linear mixed-effects model predicted score changes, with participant as a random effect, and included initial score, age, sex, treatment group, and the first 5 ancestry principal components.

RESULTS

In total, 1,270 participants (64% male) were included with a median NIHSS score of 2 (interquartile range [IQR] 1-3) and median age 68 (IQR 59-75) years. At randomization, 20% had cognitive deficits (NIHSS Cog-4 score >0) and 70% had ≥1 motor deficits (impairment score >1). At 2 years, these percentages improved to 7.2% with cognitive deficits and 30% with motor deficits. GWAS identified novel suggestive gene-impairment associations (p < 5e-6) for cognition (CAMK2D, EVX2, LINC0143, PTPRM, SGMS1, and SMAD2), motor (ACBD6, KDM4B, MARK4, PTPRS, ROBO1, and ROBO2), and global (MSR1 and ROBO2) impairments.

DISCUSSION

Defining domain-specific stroke recovery phenotypes and using longitudinal clinical trial designs can help detect novel genes associated with chronic recovery. These data support the use of granular endpoints to identify genetic associations related to stroke recovery.

Endovascular Thrombectomy with or without Bridging Thrombolysis in Acute Ischemic Stroke: A Cost-Effectiveness Analysis

BACKGROUND

There is unclear added benefit of intravenous thrombolysis (IVT) with endovascular thrombectomy (EVT). We performed a cost-effectiveness analysis to assess the cost-effectiveness of comparing EVT with IVT versus EVT alone.

METHODS

We used a decision tree to examine the short-term costs and outcomes at 90 days after the occurrence of index stroke to compare the cost-effectiveness of EVT alone with EVT plus IVT for patients with stroke. Subsequently, we developed a Markov state transition model to assess the costs and outcomes over 1-year, 5-year, and 20-year time horizons. We estimated total and incremental cost, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio.

RESULTS

The average costs per patient were estimated to be $47,304, $49,510, $59,770, and $76,561 for EVT-only strategy and $55,482, $57,751, $68,314, and $85,611 for EVT with IVT over 90 days, 1 year, 5 years, and 20 years, respectively. The cost saving of EVT-only strategy was driven by the avoided medication costs of IVT (ranging from $8,178 to $9,050). The additional IVT led to a slight decrease in QALY estimate during the 90-day time horizon (loss of 0.002 QALY), but a small gain over 1-year and 5-year time horizons (0.011 and 0.0636 QALY). At a willingness-to-pay threshold of $50,000 per QALY gained, the probabilities of EVT only being cost-effective were 100%, 100%, and 99.3% over 90-day, 1-year, and 5-year time horizons.

CONCLUSION

Our cost-effectiveness model suggested that EVT only may be cost-effective for patients with acute ischemic stroke secondary to large vessel occlusion.

Preserved Corticospinal Tract Revealed by Acute Perfusion Imaging Relates to Better Outcome After Thrombectomy in Stroke

BACKGROUND

The indication for mechanical thrombectomy (MT) in stroke patients with large vessel occlusion has been constantly expanded over the past years. Despite remarkable treatment effects at the group level in clinical trials, many patients remain severely disabled even after successful recanalization. A better understanding of this outcome variability will help to improve clinical decision-making on MT in the acute stage. Here, we test whether current outcome models can be refined by integrating information on the preservation of the corticospinal tract as a functionally crucial white matter tract derived from acute perfusion imaging.

METHODS

We retrospectively analyzed 162 patients with stroke and large vessel occlusion of the anterior circulation who were admitted to the University Medical Center Lübeck between 2014 and 2020 and underwent MT. The ischemic core was defined as fully automatized based on the acute computed tomography perfusion with cerebral blood volume data using outlier detection and clustering algorithms. Normative whole-brain structural connectivity data were used to infer whether the corticospinal tract was affected by the ischemic core or preserved. Ordinal logistic regression models were used to correlate this information with the modified Rankin Scale after 90 days.

RESULTS

The preservation of the corticospinal tract was associated with a reduced risk of a worse functional outcome in large vessel occlusion-stroke patients undergoing MT, with an odds ratio of 0.28 (95% CI, 0.15-0.53). This association was still significant after adjusting for multiple confounding covariables, such as age, lesion load, initial symptom severity, sex, stroke side, and recanalization status.

CONCLUSIONS

A preinterventional computed tomography perfusion-based surrogate of corticospinal tract preservation or disconnectivity is strongly associated with functional outcomes after MT. If validated in independent samples this concept could serve as a novel tool to improve current outcome models to better understand intersubject variability after MT in large vessel occlusion stroke.

Post-Stroke Brain Health Monitoring and Optimization: A Narrative Review

Significant advancements have been made in recent years in the acute treatment and secondary prevention of stroke. However, a large proportion of stroke survivors will go on to have enduring physical, cognitive, and psychological disabilities from suboptimal post-stroke brain health. Impaired brain health following stroke thus warrants increased attention from clinicians and researchers alike. In this narrative review based on an open timeframe search of the PubMed, Scopus, and Web of Science databases, we define post-stroke brain health and appraise the body of research focused on modifiable vascular, lifestyle, and psychosocial factors for optimizing post-stroke brain health. In addition, we make clinical recommendations for the monitoring and management of post-stroke brain health at major post-stroke transition points centered on four key intertwined domains: cognition, psychosocial health, physical functioning, and global vascular health. Finally, we discuss potential future work in the field of post-stroke brain health, including the use of remote monitoring and interventions, neuromodulation, multi-morbidity interventions, enriched environments, and the need to address inequities in post-stroke brain health. As post-stroke brain health is a relatively new, rapidly evolving, and broad clinical and research field, this narrative review aims to identify and summarize the evidence base to help clinicians and researchers tailor their own approach to integrating post-stroke brain health into their practices.

Single Nucleotide Polymorphisms Associated With Motor Recovery in Patients With Nondisabling Stroke: GWAS Study

BACKGROUND AND OBJECTIVES

Despite notable advances in genetic understanding of stroke recovery, most studies focus only on candidate genes. To date, only 2 genome-wide association studies (GWAS) have focused on stroke outcomes, but they were limited to the modified Rankin Scale (mRS). The mRS maps poorly to biological processes. Therefore, we performed a GWAS to discover single nucleotide polymorphisms (SNPs) associated with motor recovery poststroke.

METHODS

We used the Vitamin Intervention for Stroke Prevention (VISP) data set of 2,100 genotyped participants with nondisabling stroke. We included only participants who had motor impairment at randomization. Participants with a recurrent stroke during the trial were excluded. Genotyped data underwent strict quality control and imputation. The GWAS used logistic regression models with generalized estimating equations to leverage the repeated NIH Stroke Scale motor score measurements spanning 6 time points over 24 months. The primary outcome was a decrease in the motor drift score of ≥1 vs <1 at each time point. Our model estimated the odds ratio (OR) of motor improvement for each SNP after adjusting for age, sex, race, days from stroke to visit, initial motor score, VISP treatment arm, and principal components.

RESULTS

A total of 488 (64%) participants with a mean (SD) age of 66 ± 11 years were included in the GWAS. Although no associations reached genome-wide significance (p < 5 × 10-8), our analysis detected 115 suggestive associations (p < 5 × 10-6). Notably, we found multiple SNP clusters near genes with plausible neuronal repair biology mechanisms. The CLDN23 gene had the most convincing association with rs1268196-T as its most significant SNP (OR 0.32; 95% CI 0.21-0.48; p value 6.19 × 10-7). CLDN23 affects blood-brain barrier integrity, neurodevelopment, and immune cell transmigration.

DISCUSSION

We identified novel suggestive genetic associations with the first-ever motor-specific poststroke recovery GWAS. The results seem to describe a distinct stroke recovery phenotype compared with prior genetic stroke outcome studies that use outcome measures, such as the mRS. Replication and further mechanistic investigation are warranted. In addition, this study demonstrated a proof-of-principle approach to optimize statistical efficiency with longitudinal data sets for genetic discovery.

Neuropsychological outcome after cardiac arrest: results from a sub-study of the targeted hypothermia versus targeted normothermia after out-of-hospital cardiac arrest (TTM2) trial

BACKGROUND

Cognitive impairment is common following out-of-hospital cardiac arrest (OHCA), but the nature of the impairment is poorly understood. Our objective was to describe cognitive impairment in OHCA survivors, with the hypothesis that OHCA survivors would perform significantly worse on neuropsychological tests of cognition than controls with acute myocardial infarction (MI). Another aim was to investigate the relationship between cognitive performance and the associated factors of emotional problems, fatigue, insomnia, and cardiovascular risk factors following OHCA.

METHODS

This was a prospective case-control sub-study of The Targeted Hypothermia versus Targeted Normothermia after Out-of-Hospital Cardiac Arrest (TTM2) trial. Eight of 61 TTM2-sites in Sweden, Denmark, and the United Kingdom included adults with OHCA of presumed cardiac or unknown cause. A matched non-arrest control group with acute MI was recruited. At approximately 7 months post-event, we administered an extensive neuropsychological test battery and questionnaires on anxiety, depression, fatigue, and insomnia, and collected information on the cardiovascular risk factors hypertension and diabetes.

RESULTS

Of 184 eligible OHCA survivors, 108 were included, with 92 MI controls enrolled. Amongst OHCA survivors, 29% performed z-score ≤ - 1 (at least borderline-mild impairment) in ≥ 2 cognitive domains, 14% performed z-score ≤ - 2 (major impairment) in ≥ 1 cognitive domain while 54% performed without impairment in any domain. Impairment was most pronounced in episodic memory, executive functions, and processing speed. OHCA survivors performed significantly worse than MI controls in episodic memory (mean difference, MD = - 0.37, 95% confidence intervals [- 0.61, - 0.12]), verbal (MD = - 0.34 [- 0.62, - 0.07]), and visual/constructive functions (MD = - 0.26 [- 0.47, - 0.04]) on linear regressions adjusted for educational attainment and sex. When additionally adjusting for anxiety, depression, fatigue, insomnia, hypertension, and diabetes, executive functions (MD = - 0.44 [- 0.82, - 0.06]) were also worse following OHCA. Diabetes, symptoms of anxiety, depression, and fatigue were significantly associated with worse cognitive performance.

CONCLUSIONS

In our study population, cognitive impairment was generally mild following OHCA. OHCA survivors performed worse than MI controls in 3 of 6 domains. These results support current guidelines that a post-OHCA follow-up service should screen for cognitive impairment, emotional problems, and fatigue.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03543371. Registered 1 June 2018.

The relevance of rich club regions for functional outcome post-stroke is enhanced in women

This study aimed to investigate the influence of stroke lesions in predefined highly interconnected (rich-club) brain regions on functional outcome post-stroke, determine their spatial specificity and explore the effects of biological sex on their relevance. We analyzed MRI data recorded at index stroke and ~3-months modified Rankin Scale (mRS) data from patients with acute ischemic stroke enrolled in the multisite MRI-GENIE study. Spatially normalized structural stroke lesions were parcellated into 108 atlas-defined bilateral (sub)cortical brain regions. Unfavorable outcome (mRS > 2) was modeled in a Bayesian logistic regression framework. Effects of individual brain regions were captured as two compound effects for (i) six bilateral rich club and (ii) all further non-rich club regions. In spatial specificity analyses, we randomized the split into "rich club" and "non-rich club" regions and compared the effect of the actual rich club regions to the distribution of effects from 1000 combinations of six random regions. In sex-specific analyses, we introduced an additional hierarchical level in our model structure to compare male and female-specific rich club effects. A total of 822 patients (age: 64.7[15.0], 39% women) were analyzed. Rich club regions had substantial relevance in explaining unfavorable functional outcome (mean of posterior distribution: 0.08, area under the curve: 0.8). In particular, the rich club-combination had a higher relevance than 98.4% of random constellations. Rich club regions were substantially more important in explaining long-term outcome in women than in men. All in all, lesions in rich club regions were associated with increased odds of unfavorable outcome. These effects were spatially specific and more pronounced in women.

Domain-Specific Outcome Measures in Clinical Trials of Therapies Promoting Stroke Recovery: A Suggested Blueprint

Different deficits recover to different degrees and with different time courses after stroke, indicating that plasticity differs across the brain's neural systems after stroke. To capture these differences, domain-specific outcome measures have received increased attention. Such measures have potential advantages over global outcome scales, which combine recovery across many domains into a single score and so blur the ability to capture individual measures of stroke recovery. Use of a global end point to rate disability can overlook substantial recovery in specific domains, such as motor or language, and may not differentiate between good and poor recovery for specific neurological domains. In light of these points, a blueprint is proposed for using domain-specific outcome measures in stroke recovery trials. Key steps include selecting a domain in the context of preclinical data, picking a domain-specific clinical trial end point, anchoring inclusion criteria to this end point, scoring this end point both before and after treatment, and then pursuing regulatory approval on the basis of the domain-specific results. This blueprint is intended to foster clinical trials that, by using domain-specific end points, are able to demonstrate favorable results in clinical trials of therapies that promote stroke recovery.

Post Stroke Motor Recovery Genome Wide Association Study: A Domain-Specific Approach

BACKGROUND

In this genome wide association study (GWAS) we aimed to discover single nucleotide polymorphisms (SNPs) associated with motor recovery post-stroke.

METHODS

We used the Vitamin Intervention for Stroke Prevention (VISP) dataset of 2,100 genotyped patients with non-disabling stroke. Of these, 488 patients had motor impairment at enrollment. Genotyped data underwent strict quality control and imputation. The GWAS utilized logistic regression models with generalized estimating equations (GEE) to leverage the repeated NIH Stroke Scale (NIHSS) motor score measurements spanning 6 time points over 24 months. The primary outcome was a decrease in the motor drift score of ≥ 1 vs. < 1 at each timepoint. Our model estimated the odds ratio of motor improvement for each SNP after adjusting for age, sex, race, days from stroke to visit, initial motor score, VISP treatment arm, and principal components.

RESULTS

Although no associations reached genome-wide significance (p < 5 × 10 ^-8 ), our analysis detected 115 suggestive associations (p < 5 × 10 ^-6 ). Notably, we found multiple SNP clusters near genes with plausible neuronal repair biology mechanisms. The CLDN23 gene had the most convincing association which affects blood-brain barrier integrity, neurodevelopment, and immune cell transmigration.

CONCLUSION

We identified novel suggestive genetic associations with the first ever motor-specific post stroke recovery GWAS. The results seem to describe a distinct stroke recovery phenotype compared to prior genetic stroke outcome studies that use outcome measures, like the mRS. Replication and further mechanistic investigation are warranted. Additionally, this study demonstrated a proof-of-principle approach to optimize statistical efficiency with longitudinal datasets for genetic discovery.

Clinically Applicable Experimental Design and Considerations for Stroke Recovery Preclinical Studies

Development of stroke recovery therapies is an active field of research and represents an opportunity to reduce the global impact of stroke as the leading cause of acquired, long-term disability in adults. The negative outcomes of recent large-scale clinical trials have highlighted deficiencies in the translational process and endanger the trajectory of post-stroke recovery research. Because of this, a number of strategies have been recommended by experts to better navigate the translational pipeline. To assist the field in advancing to the next stage for successful clinical translation, the goal of this chapter is to discuss concepts relevant to the experimental design of in vivo preclinical pharmacological studies to make them clinically relevant and informative for future trials.

Association of Stroke Lesion Pattern and White Matter Hyperintensity Burden With Stroke Severity and Outcome

BACKGROUND AND OBJECTIVES

To examine whether high white matter hyperintensity (WMH) burden is associated with greater stroke severity and worse functional outcomes in lesion pattern-specific ways.

METHODS

MR neuroimaging and NIH Stroke Scale data at index stroke and the modified Rankin Scale (mRS) score at 3-6 months after stroke were obtained from the MRI-Genetics Interface Exploration study of patients with acute ischemic stroke (AIS). Individual WMH volume was automatically derived from fluid-attenuated inversion recovery images. Stroke lesions were automatically segmented from diffusion-weighted imaging (DWI) images, parcellated into atlas-defined brain regions and further condensed to 10 lesion patterns via machine learning-based dimensionality reduction. Stroke lesion effects on AIS severity and unfavorable outcomes (mRS score >2) were modeled within purpose-built Bayesian linear and logistic regression frameworks. Interaction effects between stroke lesions and a high vs low WMH burden were integrated via hierarchical model structures. Models were adjusted for age, age2, sex, total DWI lesion and WMH volumes, and comorbidities. Data were split into derivation and validation cohorts.

RESULTS

A total of 928 patients with AIS contributed to acute stroke severity analyses (age: 64.8 [14.5] years, 40% women) and 698 patients to long-term functional outcome analyses (age: 65.9 [14.7] years, 41% women). Stroke severity was mainly explained by lesions focused on bilateral subcortical and left hemispherically pronounced cortical regions across patients with both a high and low WMH burden. Lesions centered on left-hemispheric insular, opercular, and inferior frontal regions and lesions affecting right-hemispheric temporoparietal regions had more pronounced effects on stroke severity in case of high compared with low WMH burden. Unfavorable outcomes were predominantly explained by lesions in bilateral subcortical regions. In difference to the lesion location-specific WMH effects on stroke severity, higher WMH burden increased the odds of unfavorable outcomes independent of lesion location.

DISCUSSION

Higher WMH burden may be associated with an increased stroke severity in case of stroke lesions involving left-hemispheric insular, opercular, and inferior frontal regions (potentially linked to language functions) and right-hemispheric temporoparietal regions (potentially linked to attention). Our findings suggest that patients with specific constellations of WMH burden and lesion locations may have greater benefits from acute recanalization treatments. Future clinical studies are warranted to systematically assess this assumption and guide more tailored treatment decisions.

Deep profiling of multiple ischemic lesions in a large, multi-center cohort: Frequency, spatial distribution, and associations to clinical characteristics

Background purpose

A substantial number of patients with acute ischemic stroke (AIS) experience multiple acute lesions (MAL). We here aimed to scrutinize MAL in a large radiologically deep-phenotyped cohort.

Materials and methods

Analyses relied upon imaging and clinical data from the international MRI-GENIE study. Imaging data comprised both Fluid-attenuated inversion recovery (FLAIR) for white matter hyperintensity (WMH) burden estimation and diffusion-weighted imaging (DWI) sequences for the assessment of acute stroke lesions. The initial step featured the systematic evaluation of occurrences of MAL within one and several vascular supply territories. Associations between MAL and important imaging and clinical characteristics were subsequently determined. The interaction effect between single and multiple lesion status and lesion volume was estimated by means of Bayesian hierarchical regression modeling for both stroke severity and functional outcome.

Results

We analyzed 2,466 patients (age = 63.4 ± 14.8, 39% women), 49.7% of which presented with a single lesion. Another 37.4% experienced MAL in a single vascular territory, while 12.9% featured lesions in multiple vascular territories. Within most territories, MAL occurred as frequently as single lesions (ratio ∼1:1). Only the brainstem region comprised fewer patients with MAL (ratio 1:4). Patients with MAL presented with a significantly higher lesion volume and acute NIHSS (7.7 vs. 1.7 ml and 4 vs. 3, p FDR < 0.001). In contrast, patients with a single lesion were characterized by a significantly higher WMH burden (6.1 vs. 5.3 ml, p FDR = 0.048). Functional outcome did not differ significantly between patients with single versus multiple lesions. Bayesian analyses suggested that the association between lesion volume and stroke severity between single and multiple lesions was the same in case of anterior circulation stroke. In case of posterior circulation stroke, lesion volume was linked to a higher NIHSS only among those with MAL.

Conclusion

Multiple lesions, especially those within one vascular territory, occurred more frequently than previously reported. Overall, multiple lesions were distinctly linked to a higher acute stroke severity, a higher total DWI lesion volume and a lower WMH lesion volume. In posterior circulation stroke, lesion volume was linked to a higher stroke severity in multiple lesions only.

Stroke recovery phenotyping through network trajectory approaches and graph neural networks

Stroke is a leading cause of neurological injury characterized by impairments in multiple neurological domains including cognition, language, sensory and motor functions. Clinical recovery in these domains is tracked using a wide range of measures that may be continuous, ordinal, interval or categorical in nature, which can present challenges for multivariate regression approaches. This has hindered stroke researchers’ ability to achieve an integrated picture of the complex time-evolving interactions among symptoms. Here, we use tools from network science and machine learning that are particularly well-suited to extracting underlying patterns in such data, and may assist in prediction of recovery patterns. To demonstrate the utility of this approach, we analyzed data from the NINDS tPA trial using the Trajectory Profile Clustering (TPC) method to identify distinct stroke recovery patterns for 11 different neurological domains at 5 discrete time points. Our analysis identified 3 distinct stroke trajectory profiles that align with clinically relevant stroke syndromes, characterized both by distinct clusters of symptoms, as well as differing degrees of symptom severity. We then validated our approach using graph neural networks to determine how well our model performed predictively for stratifying patients into these trajectory profiles at early vs. later time points post-stroke. We demonstrate that trajectory profile clustering is an effective method for identifying clinically relevant recovery subtypes in multidimensional longitudinal datasets, and for early prediction of symptom progression subtypes in individual patients. This paper is the first work introducing network trajectory approaches for stroke recovery phenotyping, and is aimed at enhancing the translation of such novel computational approaches for practical clinical application.

Association of Modified Rankin Scale With Recovery Phenotypes in Patients With Upper Extremity Weakness After Stroke

BACKGROUND

Precise measurement of outcomes is essential for stroke trials and clinical care. Prior research has highlighted conceptual differences between global outcome measures such as the Modified Rankin Scale (mRS) and domain-specific measures (e.g. motor, sensory, language or cognitive function). This study related motor phenotypes to the mRS, specifically aiming to (1) determine whether mRS levels distinguish motor impairment and function phenotypes, and (2) compare mRS outcomes to meaningful changes in impairment and function from acute to subacute recovery after stroke.

METHODS

Patients with upper extremity weakness after ischemic stroke were assessed with a battery of impairment and functional measures within the first week and at 90-days post-stroke. Impairment and functional outcomes were examined in relation to 90-day mRS scores. Clinically meaningful changes in motor impairment, activities of daily living, and mobility were examined in relation to 90-day mRS.

RESULTS

In this cohort of n = 73 stroke patients, impairment and functional outcomes were associated with 90-day mRS scores but showed substantial variability within individual mRS levels: within mRS level 2, upper extremity impairment ranged from near hemiplegia (with an upper extremity Fugl-Meyer 8) to no deficits (upper extremity Fugl-Meyer 66). Overall, there were few differences in impairment and functional outcomes between adjacent mRS levels. While some outcome measures were significantly different between mRS levels 3 and 4 (Nine-Hole Peg, Leg Motor, Gait Velocity, Timed Up and Go, National Institutes of Health Stroke Scale, and Barthel Index), none of the outcome measures differed between mRS levels 1 and 2. Fugl-Meyer and Grip Strength were not different between any adjacent mRS levels. A substantial number of patients experienced clinically meaningful changes in impairment and function in the first 90 days post-stroke but did not achieve good mRS outcome (mRS ≤ 2).

CONCLUSIONS

The mRS broadly relates to domain-specific outcomes after stroke confirming its established value in stroke trials, but it does not precisely distinguish differences in impairment and function nor does it sufficiently capture meaningful clinical changes across impairment, ADL status, and mobility. These findings underscore the potential utility of incorporating detailed phenotypic measures alongside the mRS in future stroke trials.